but critics think chris christie's weight is a big obstacle. >> but now christie is blasting those critics saying, hey, enough is enough. with more on this, here's abc's dan harris. >> this is just another hack who wants five minutes on tv. >> reporter: chris christie displaying his famous candor, reacting to dr. connie mariano, the former white house doctor, who, on cnn, called the governor a time bomb. >> i'm a physician more than a democrat or republican and i worry about this man dying in office. >> she must be a genius. >> reporter: the governor questioned how she could diagnose him from her office in arizona. >> it's completely irresponsible. my 12-year-old son came to me last night and said, dad, are you going to die? >> hey, bring it, fat boy! >> chris christie said he's not going to run for re-election next year. he's like, i'll collapse that bridge when i get to it. >> reporter: his weight has been constant source of attention. christie who was slender and athletic as a young man, insists his health is still good. >> if you talk to anybody in the room that's struggled with their